[dpdk-stable] [PATCH] net/i40e: fix incorrect hash look up table

[Shougang Wang]

The hash look up table(LUT) will not be initializing when starting
testpmd with --disable-rss. So that some queues in LUT will be invalid
if rx queues is less than last time. When enable RSS by creating RSS rule,
some packets will not be into the valid queues.
This patch fixes this issue by initializing the LUT when creating an RSS
rule.

Fixes: feaae285b342 ("net/i40e: support hash configuration in RSS flow")
Cc: stable at dpdk.org

Signed-off-by: Shougang Wang <shougangx.wang at intel.com>
---
 drivers/net/i40e/i40e_ethdev.c | 52 ++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
index 393b5320f..2a92bd8ef 100644
--- a/drivers/net/i40e/i40e_ethdev.c
+++ b/drivers/net/i40e/i40e_ethdev.c
@@ -13070,6 +13070,49 @@ i40e_rss_conf_init(struct i40e_rte_flow_rss_conf *out,
 	return 0;
 }
 
+static int
+i40e_rss_init_lut(struct i40e_pf *pf)
+{
+	struct i40e_hw *hw = I40E_PF_TO_HW(pf);
+	uint32_t lut = 0;
+	uint16_t j, num;
+	uint32_t i;
+
+	/*
+	 * If both VMDQ and RSS enabled, not all of PF queues are configured.
+	 * It's necessary to calculate the actual PF queues that are configured.
+	 */
+	if (pf->dev_data->dev_conf.rxmode.mq_mode & ETH_MQ_RX_VMDQ_FLAG)
+		num = i40e_pf_calc_configured_queues_num(pf);
+	else
+		num = pf->dev_data->nb_rx_queues;
+
+	num = RTE_MIN(num, I40E_MAX_Q_PER_TC);
+	PMD_INIT_LOG(INFO, "Max of contiguous %u PF queues are configured",
+		     num);
+
+	if (num == 0) {
+		PMD_INIT_LOG(ERR,
+			"No PF queues are configured to enable RSS for port %u",
+			pf->dev_data->port_id);
+		return -ENOTSUP;
+	}
+
+	if (pf->adapter->rss_reta_updated == 0) {
+		for (i = 0, j = 0; i < hw->func_caps.rss_table_size; i++, j++) {
+			if (j == num)
+				j = 0;
+			lut = (lut << 8) | (j & ((0x1 <<
+				hw->func_caps.rss_table_entry_width) - 1));
+			if ((i & 3) == 3)
+				I40E_WRITE_REG(hw, I40E_PFQF_HLUT(i >> 2),
+					       rte_bswap32(lut));
+		}
+	}
+
+	return 0;
+}
+
 /* Write HENA register to enable hash */
 static int
 i40e_rss_hash_set(struct i40e_pf *pf, struct i40e_rte_flow_rss_conf *rss_conf)
@@ -13318,12 +13361,21 @@ static int
 i40e_rss_enable_hash(struct i40e_pf *pf,
 		struct i40e_rte_flow_rss_conf *conf)
 {
+	enum rte_eth_rx_mq_mode mq_mode = pf->dev_data->dev_conf.rxmode.mq_mode;
 	struct i40e_rte_flow_rss_conf *rss_info = &pf->rss_info;
 	struct i40e_rte_flow_rss_conf rss_conf;
 
 	if (!(conf->conf.types & pf->adapter->flow_types_mask))
 		return -ENOTSUP;
 
+	/*
+	 * If the RSS is disabled before this, the LUT is uninitialized. 
+	 * So it is necessary to initialize it here.
+	 */
+	if (!(mq_mode & ETH_MQ_RX_RSS_FLAG) && !pf->rss_info.conf.queue_num)
+		if (i40e_rss_init_lut(pf))
+			return -ENOTSUP;
+
 	memset(&rss_conf, 0, sizeof(rss_conf));
 	rte_memcpy(&rss_conf, conf, sizeof(rss_conf));
 
-- 
2.17.1